from django import forms, template
from django.forms.formsets import all_valid
from django.forms.models import modelform_factory, inlineformset_factory
from django.forms.models import BaseInlineFormSet
from django.contrib.contenttypes.models import ContentType
from django.contrib.admin import widgets
from django.contrib.admin import helpers
from django.contrib.admin.util import unquote, flatten_fieldsets, get_deleted_objects
from django.core.exceptions import PermissionDenied
from django.db import models, transaction
from django.http import Http404, HttpResponse, HttpResponseRedirect
from django.shortcuts import get_object_or_404, render_to_response
from django.utils.functional import update_wrapper
from django.utils.html import escape
from django.utils.safestring import mark_safe
from django.utils.functional import curry
from django.utils.text import capfirst, get_text_list
from django.utils.translation import ugettext as _
from django.utils.encoding import force_unicode
try:
    set
except NameError:
    from sets import Set as set     # Python 2.3 fallback

HORIZONTAL, VERTICAL = 1, 2
# returns the <ul> class for a given radio_admin field
get_ul_class = lambda x: 'radiolist%s' % ((x == HORIZONTAL) and ' inline' or '')

class IncorrectLookupParameters(Exception):
    pass

# Defaults for formfield_overrides. ModelAdmin subclasses can change this
# by adding to ModelAdmin.formfield_overrides.
    
FORMFIELD_FOR_DBFIELD_DEFAULTS = {
    models.DateTimeField: { 
        'form_class': forms.SplitDateTimeField,
        'widget': widgets.AdminSplitDateTime 
    },
    models.DateField:    {'widget': widgets.AdminDateWidget},
    models.TimeField:    {'widget': widgets.AdminTimeWidget},
    models.TextField:    {'widget': widgets.AdminTextareaWidget},
    models.URLField:     {'widget': widgets.AdminURLFieldWidget},
    models.IntegerField: {'widget': widgets.AdminIntegerFieldWidget},
    models.CharField:    {'widget': widgets.AdminTextInputWidget},
    models.ImageField:   {'widget': widgets.AdminFileWidget},
    models.FileField:    {'widget': widgets.AdminFileWidget},
}


class BaseModelAdmin(object):
    """Functionality common to both ModelAdmin and InlineAdmin."""
    
    raw_id_fields = ()
    fields = None
    exclude = None
    fieldsets = None
    form = forms.ModelForm
    filter_vertical = ()
    filter_horizontal = ()
    radio_fields = {}
    prepopulated_fields = {}
    formfield_overrides = {}
    
    def __init__(self):
        self.formfield_overrides = dict(FORMFIELD_FOR_DBFIELD_DEFAULTS, **self.formfield_overrides)
    
    def formfield_for_dbfield(self, db_field, **kwargs):
        """
        Hook for specifying the form Field instance for a given database Field
        instance.
        
        If kwargs are given, they're passed to the form Field's constructor.
        """
        request = kwargs.pop("request", None)
        
        # If the field specifies choices, we don't need to look for special
        # admin widgets - we just need to use a select widget of some kind.
        if db_field.choices:
            return self.formfield_for_choice_field(db_field, request, **kwargs)
        
        # ForeignKey or ManyToManyFields
        if isinstance(db_field, (models.ForeignKey, models.ManyToManyField)):
            # Combine the field kwargs with any options for formfield_overrides.
            # Make sure the passed in **kwargs override anything in 
            # formfield_overrides because **kwargs is more specific, and should
            # always win.
            if db_field.__class__ in self.formfield_overrides:
                kwargs = dict(self.formfield_overrides[db_field.__class__], **kwargs)
            
            # Get the correct formfield.
            if isinstance(db_field, models.ForeignKey):
                formfield = self.formfield_for_foreignkey(db_field, request, **kwargs)
            elif isinstance(db_field, models.ManyToManyField):
                formfield = self.formfield_for_manytomany(db_field, request, **kwargs)
            
            # For non-raw_id fields, wrap the widget with a wrapper that adds
            # extra HTML -- the "add other" interface -- to the end of the
            # rendered output. formfield can be None if it came from a 
            # OneToOneField with parent_link=True or a M2M intermediary.
            if formfield and db_field.name not in self.raw_id_fields:
                formfield.widget = widgets.RelatedFieldWidgetWrapper(formfield.widget, db_field.rel, self.admin_site)

            return formfield
                    
        # If we've got overrides for the formfield defined, use 'em. **kwargs
        # passed to formfield_for_dbfield override the defaults.
        if db_field.__class__ in self.formfield_overrides:
            kwargs = dict(self.formfield_overrides[db_field.__class__], **kwargs)
            return db_field.formfield(**kwargs)
                        
        # For any other type of field, just call its formfield() method.
        return db_field.formfield(**kwargs)
        
    def formfield_for_choice_field(self, db_field, request=None, **kwargs):
        """
        Get a form Field for a database Field that has declared choices.
        """
        # If the field is named as a radio_field, use a RadioSelect
        if db_field.name in self.radio_fields:
            # Avoid stomping on custom widget/choices arguments.
            if 'widget' not in kwargs:
                kwargs['widget'] = widgets.AdminRadioSelect(attrs={
                    'class': get_ul_class(self.radio_fields[db_field.name]),
                })
            if 'choices' not in kwargs:
                kwargs['choices'] = db_field.get_choices(
                    include_blank = db_field.blank,
                    blank_choice=[('', _('None'))]
                )
        return db_field.formfield(**kwargs)
    
    def formfield_for_foreignkey(self, db_field, request=None, **kwargs):
        """
        Get a form Field for a ForeignKey.
        """
        if db_field.name in self.raw_id_fields:
            kwargs['widget'] = widgets.ForeignKeyRawIdWidget(db_field.rel)
        elif db_field.name in self.radio_fields:
            kwargs['widget'] = widgets.AdminRadioSelect(attrs={
                'class': get_ul_class(self.radio_fields[db_field.name]),
            })
            kwargs['empty_label'] = db_field.blank and _('None') or None
        
        return db_field.formfield(**kwargs)

    def formfield_for_manytomany(self, db_field, request=None, **kwargs):
        """
        Get a form Field for a ManyToManyField.
        """
        # If it uses an intermediary model, don't show field in admin.
        if db_field.rel.through is not None:
            return None
        
        if db_field.name in self.raw_id_fields:
            kwargs['widget'] = widgets.ManyToManyRawIdWidget(db_field.rel)
            kwargs['help_text'] = ''
        elif db_field.name in (list(self.filter_vertical) + list(self.filter_horizontal)):
            kwargs['widget'] = widgets.FilteredSelectMultiple(db_field.verbose_name, (db_field.name in self.filter_vertical))
        
        return db_field.formfield(**kwargs)
    
    def _declared_fieldsets(self):
        if self.fieldsets:
            return self.fieldsets
        elif self.fields:
            return [(None, {'fields': self.fields})]
        return None
    declared_fieldsets = property(_declared_fieldsets)

class ModelAdmin(BaseModelAdmin):
    "Encapsulates all admin options and functionality for a given model."
    __metaclass__ = forms.MediaDefiningClass
    
    list_display = ('__str__',)
    list_display_links = ()
    list_filter = ()
    list_select_related = False
    list_per_page = 100
    search_fields = ()
    date_hierarchy = None
    save_as = False
    save_on_top = False
    ordering = None
    inlines = []
    
    # Custom templates (designed to be over-ridden in subclasses)
    change_form_template = None
    change_list_template = None
    delete_confirmation_template = None
    object_history_template = None
    
    def __init__(self, model, admin_site):
        self.model = model
        self.opts = model._meta
        self.admin_site = admin_site
        self.inline_instances = []
        for inline_class in self.inlines:
            inline_instance = inline_class(self.model, self.admin_site)
            self.inline_instances.append(inline_instance)
        super(ModelAdmin, self).__init__()
        
    def get_urls(self):
        from django.conf.urls.defaults import patterns, url
        
        def wrap(view):
            def wrapper(*args, **kwargs):
                return self.admin_site.admin_view(view)(*args, **kwargs)
            return update_wrapper(wrapper, view)
        
        info = self.admin_site.name, self.model._meta.app_label, self.model._meta.module_name
        
        urlpatterns = patterns('',
            url(r'^$',
                wrap(self.changelist_view),
                name='%sadmin_%s_%s_changelist' % info),
            url(r'^add/$',
                wrap(self.add_view),
                name='%sadmin_%s_%s_add' % info),
            url(r'^(.+)/history/$',
                wrap(self.history_view),
                name='%sadmin_%s_%s_history' % info),
            url(r'^(.+)/delete/$',
                wrap(self.delete_view),
                name='%sadmin_%s_%s_delete' % info),
            url(r'^(.+)/$',
                wrap(self.change_view),
                name='%sadmin_%s_%s_change' % info),
        )
        return urlpatterns
    
    def urls(self):
        return self.get_urls()
    urls = property(urls)
    
    def _media(self):
        from django.conf import settings
        
        js = ['js/core.js', 'js/admin/RelatedObjectLookups.js']
        if self.prepopulated_fields:
            js.append('js/urlify.js')
        if self.opts.get_ordered_objects():
            js.extend(['js/getElementsBySelector.js', 'js/dom-drag.js' , 'js/admin/ordering.js'])
        
        return forms.Media(js=['%s%s' % (settings.ADMIN_MEDIA_PREFIX, url) for url in js])
    media = property(_media)
    
    def has_add_permission(self, request):
        "Returns True if the given request has permission to add an object."
        opts = self.opts
        return request.user.has_perm(opts.app_label + '.' + opts.get_add_permission())
    
    def has_change_permission(self, request, obj=None):
        """
        Returns True if the given request has permission to change the given
        Django model instance.
        
        If `obj` is None, this should return True if the given request has
        permission to change *any* object of the given type.
        """
        opts = self.opts
        return request.user.has_perm(opts.app_label + '.' + opts.get_change_permission())
    
    def has_delete_permission(self, request, obj=None):
        """
        Returns True if the given request has permission to change the given
        Django model instance.
        
        If `obj` is None, this should return True if the given request has
        permission to delete *any* object of the given type.
        """
        opts = self.opts
        return request.user.has_perm(opts.app_label + '.' + opts.get_delete_permission())
    
    def queryset(self, request):
        """
        Returns a QuerySet of all model instances that can be edited by the
        admin site. This is used by changelist_view.
        """
        qs = self.model._default_manager.get_query_set()
        # TODO: this should be handled by some parameter to the ChangeList.
        ordering = self.ordering or () # otherwise we might try to *None, which is bad ;)
        if ordering:
            qs = qs.order_by(*ordering)
        return qs
    
    def get_fieldsets(self, request, obj=None):
        "Hook for specifying fieldsets for the add form."
        if self.declared_fieldsets:
            return self.declared_fieldsets
        form = self.get_form(request, obj)
        return [(None, {'fields': form.base_fields.keys()})]
    
    def get_form(self, request, obj=None, **kwargs):
        """
        Returns a Form class for use in the admin add view. This is used by
        add_view and change_view.
        """
        if self.declared_fieldsets:
            fields = flatten_fieldsets(self.declared_fieldsets)
        else:
            fields = None
        if self.exclude is None:
            exclude = []
        else:
            exclude = list(self.exclude)
        defaults = {
            "form": self.form,
            "fields": fields,
            "exclude": exclude + kwargs.get("exclude", []),
            "formfield_callback": curry(self.formfield_for_dbfield, request=request),
        }
        defaults.update(kwargs)
        return modelform_factory(self.model, **defaults)
    
    def get_formsets(self, request, obj=None):
        for inline in self.inline_instances:
            yield inline.get_formset(request, obj)
    
    def log_addition(self, request, object):
        """
        Log that an object has been successfully added.
        
        The default implementation creates an admin LogEntry object.
        """
        from django.contrib.admin.models import LogEntry, ADDITION
        LogEntry.objects.log_action(
            user_id         = request.user.pk,
            content_type_id = ContentType.objects.get_for_model(object).pk,
            object_id       = object.pk,
            object_repr     = force_unicode(object),
            action_flag     = ADDITION
        )
    
    def log_change(self, request, object, message):
        """
        Log that an object has been successfully changed.
        
        The default implementation creates an admin LogEntry object.
        """
        from django.contrib.admin.models import LogEntry, CHANGE
        LogEntry.objects.log_action(
            user_id         = request.user.pk,
            content_type_id = ContentType.objects.get_for_model(object).pk,
            object_id       = object.pk,
            object_repr     = force_unicode(object),
            action_flag     = CHANGE,
            change_message  = message
        )
    
    def log_deletion(self, request, object, object_repr):
        """
        Log that an object has been successfully deleted. Note that since the
        object is deleted, it might no longer be safe to call *any* methods
        on the object, hence this method getting object_repr.
        
        The default implementation creates an admin LogEntry object.
        """
        from django.contrib.admin.models import LogEntry, DELETION
        LogEntry.objects.log_action(
            user_id         = request.user.id,
            content_type_id = ContentType.objects.get_for_model(self.model).pk,
            object_id       = object.pk,
            object_repr     = object_repr,
            action_flag     = DELETION
        )
    
    
    def construct_change_message(self, request, form, formsets):
        """
        Construct a change message from a changed object.
        """
        change_message = []
        if form.changed_data:
            change_message.append(_('Changed %s.') % get_text_list(form.changed_data, _('and')))
        
        if formsets:
            for formset in formsets:
                for added_object in formset.new_objects:
                    change_message.append(_('Added %(name)s "%(object)s".')
                                          % {'name': added_object._meta.verbose_name,
                                             'object': force_unicode(added_object)})
                for changed_object, changed_fields in formset.changed_objects:
                    change_message.append(_('Changed %(list)s for %(name)s "%(object)s".')
                                          % {'list': get_text_list(changed_fields, _('and')),
                                             'name': changed_object._meta.verbose_name,
                                             'object': force_unicode(changed_object)})
                for deleted_object in formset.deleted_objects:
                    change_message.append(_('Deleted %(name)s "%(object)s".')
                                          % {'name': deleted_object._meta.verbose_name,
                                             'object': force_unicode(deleted_object)})
        change_message = ' '.join(change_message)
        return change_message or _('No fields changed.')
    
    def message_user(self, request, message):
        """
        Send a message to the user. The default implementation
        posts a message using the auth Message object.
        """
        request.user.message_set.create(message=message)
    
    def save_form(self, request, form, change):
        """
        Given a ModelForm return an unsaved instance. ``change`` is True if
        the object is being changed, and False if it's being added.
        """
        return form.save(commit=False)
    
    def save_model(self, request, obj, form, change):
        """
        Given a model instance save it to the database.
        """
        obj.save()
    
    def save_formset(self, request, form, formset, change):
        """
        Given an inline formset save it to the database.
        """
        formset.save()
    
    def render_change_form(self, request, context, add=False, change=False, form_url='', obj=None):
        opts = self.model._meta
        app_label = opts.app_label
        ordered_objects = opts.get_ordered_objects()
        context.update({
            'add': add,
            'change': change,
            'has_add_permission': self.has_add_permission(request),
            'has_change_permission': self.has_change_permission(request, obj),
            'has_delete_permission': self.has_delete_permission(request, obj),
            'has_file_field': True, # FIXME - this should check if form or formsets have a FileField,
            'has_absolute_url': hasattr(self.model, 'get_absolute_url'),
            'ordered_objects': ordered_objects,
            'form_url': mark_safe(form_url),
            'opts': opts,
            'content_type_id': ContentType.objects.get_for_model(self.model).id,
            'save_as': self.save_as,
            'save_on_top': self.save_on_top,
            'root_path': self.admin_site.root_path,
        })
        return render_to_response(self.change_form_template or [
            "admin/%s/%s/change_form.html" % (app_label, opts.object_name.lower()),
            "admin/%s/change_form.html" % app_label,
            "admin/change_form.html"
        ], context, context_instance=template.RequestContext(request))
    
    def response_add(self, request, obj, post_url_continue='../%s/'):
        """
        Determines the HttpResponse for the add_view stage.
        """
        opts = obj._meta
        pk_value = obj._get_pk_val()
        
        msg = _('The %(name)s "%(obj)s" was added successfully.') % {'name': force_unicode(opts.verbose_name), 'obj': force_unicode(obj)}
        # Here, we distinguish between different save types by checking for
        # the presence of keys in request.POST.
        if request.POST.has_key("_continue"):
            self.message_user(request, msg + ' ' + _("You may edit it again below."))
            if request.POST.has_key("_popup"):
                post_url_continue += "?_popup=1"
            return HttpResponseRedirect(post_url_continue % pk_value)
        
        if request.POST.has_key("_popup"):
            return HttpResponse('<script type="text/javascript">opener.dismissAddAnotherPopup(window, "%s", "%s");</script>' % \
                # escape() calls force_unicode.
                (escape(pk_value), escape(obj)))
        elif request.POST.has_key("_addanother"):
            self.message_user(request, msg + ' ' + (_("You may add another %s below.") % force_unicode(opts.verbose_name)))
            return HttpResponseRedirect(request.path)
        else:
            self.message_user(request, msg)
            
            # Figure out where to redirect. If the user has change permission,
            # redirect to the change-list page for this object. Otherwise,
            # redirect to the admin index.
            if self.has_change_permission(request, None):
                post_url = '../'
            else:
                post_url = '../../../'
            return HttpResponseRedirect(post_url)
    
    def response_change(self, request, obj):
        """
        Determines the HttpResponse for the change_view stage.
        """
        opts = obj._meta
        pk_value = obj._get_pk_val()
        
        msg = _('The %(name)s "%(obj)s" was changed successfully.') % {'name': force_unicode(opts.verbose_name), 'obj': force_unicode(obj)}
        if request.POST.has_key("_continue"):
            self.message_user(request, msg + ' ' + _("You may edit it again below."))
            if request.REQUEST.has_key('_popup'):
                return HttpResponseRedirect(request.path + "?_popup=1")
            else:
                return HttpResponseRedirect(request.path)
        elif request.POST.has_key("_saveasnew"):
            msg = _('The %(name)s "%(obj)s" was added successfully. You may edit it again below.') % {'name': force_unicode(opts.verbose_name), 'obj': obj}
            self.message_user(request, msg)
            return HttpResponseRedirect("../%s/" % pk_value)
        elif request.POST.has_key("_addanother"):
            self.message_user(request, msg + ' ' + (_("You may add another %s below.") % force_unicode(opts.verbose_name)))
            return HttpResponseRedirect("../add/")
        else:
            self.message_user(request, msg)
            return HttpResponseRedirect("../")
    
    def add_view(self, request, form_url='', extra_context=None):
        "The 'add' admin view for this model."
        model = self.model
        opts = model._meta
        
        if not self.has_add_permission(request):
            raise PermissionDenied
        
        ModelForm = self.get_form(request)
        formsets = []
        if request.method == 'POST':
            form = ModelForm(request.POST, request.FILES)
            if form.is_valid():
                form_validated = True
                new_object = self.save_form(request, form, change=False)
            else:
                form_validated = False
                new_object = self.model()
            for FormSet in self.get_formsets(request):
                formset = FormSet(data=request.POST, files=request.FILES,
                                  instance=new_object,
                                  save_as_new=request.POST.has_key("_saveasnew"))
                formsets.append(formset)
            if all_valid(formsets) and form_validated:
                self.save_model(request, new_object, form, change=False)
                form.save_m2m()
                for formset in formsets:
                    self.save_formset(request, form, formset, change=False)
                
                self.log_addition(request, new_object)
                return self.response_add(request, new_object)
        else:
            # Prepare the dict of initial data from the request.
            # We have to special-case M2Ms as a list of comma-separated PKs.
            initial = dict(request.GET.items())
            for k in initial:
                try:
                    f = opts.get_field(k)
                except models.FieldDoesNotExist:
                    continue
                if isinstance(f, models.ManyToManyField):
                    initial[k] = initial[k].split(",")
            form = ModelForm(initial=initial)
            for FormSet in self.get_formsets(request):
                formset = FormSet(instance=self.model())
                formsets.append(formset)
        
        adminForm = helpers.AdminForm(form, list(self.get_fieldsets(request)), self.prepopulated_fields)
        media = self.media + adminForm.media
        
        inline_admin_formsets = []
        for inline, formset in zip(self.inline_instances, formsets):
            fieldsets = list(inline.get_fieldsets(request))
            inline_admin_formset = helpers.InlineAdminFormSet(inline, formset, fieldsets)
            inline_admin_formsets.append(inline_admin_formset)
            media = media + inline_admin_formset.media
        
        context = {
            'title': _('Add %s') % force_unicode(opts.verbose_name),
            'adminform': adminForm,
            'is_popup': request.REQUEST.has_key('_popup'),
            'show_delete': False,
            'media': mark_safe(media),
            'inline_admin_formsets': inline_admin_formsets,
            'errors': helpers.AdminErrorList(form, formsets),
            'root_path': self.admin_site.root_path,
            'app_label': opts.app_label,
        }
        context.update(extra_context or {})
        return self.render_change_form(request, context, add=True)
    add_view = transaction.commit_on_success(add_view)
    
    def change_view(self, request, object_id, extra_context=None):
        "The 'change' admin view for this model."
        model = self.model
        opts = model._meta
        
        try:
            obj = model._default_manager.get(pk=unquote(object_id))
        except model.DoesNotExist:
            # Don't raise Http404 just yet, because we haven't checked
            # permissions yet. We don't want an unauthenticated user to be able
            # to determine whether a given object exists.
            obj = None
        
        if not self.has_change_permission(request, obj):
            raise PermissionDenied
        
        if obj is None:
            raise Http404(_('%(name)s object with primary key %(key)r does not exist.') % {'name': force_unicode(opts.verbose_name), 'key': escape(object_id)})
        
        if request.method == 'POST' and request.POST.has_key("_saveasnew"):
            return self.add_view(request, form_url='../../add/')
        
        ModelForm = self.get_form(request, obj)
        formsets = []
        if request.method == 'POST':
            form = ModelForm(request.POST, request.FILES, instance=obj)
            if form.is_valid():
                form_validated = True
                new_object = self.save_form(request, form, change=True)
            else:
                form_validated = False
                new_object = obj
            for FormSet in self.get_formsets(request, new_object):
                formset = FormSet(request.POST, request.FILES,
                                  instance=new_object)
                formsets.append(formset)
            
            if all_valid(formsets) and form_validated:
                self.save_model(request, new_object, form, change=True)
                form.save_m2m()
                for formset in formsets:
                    self.save_formset(request, form, formset, change=True)
                
                change_message = self.construct_change_message(request, form, formsets)
                self.log_change(request, new_object, change_message)
                return self.response_change(request, new_object)
        
        else:
            form = ModelForm(instance=obj)
            for FormSet in self.get_formsets(request, obj):
                formset = FormSet(instance=obj)
                formsets.append(formset)
        
        adminForm = helpers.AdminForm(form, self.get_fieldsets(request, obj), self.prepopulated_fields)
        media = self.media + adminForm.media
        
        inline_admin_formsets = []
        for inline, formset in zip(self.inline_instances, formsets):
            fieldsets = list(inline.get_fieldsets(request, obj))
            inline_admin_formset = helpers.InlineAdminFormSet(inline, formset, fieldsets)
            inline_admin_formsets.append(inline_admin_formset)
            media = media + inline_admin_formset.media
        
        context = {
            'title': _('Change %s') % force_unicode(opts.verbose_name),
            'adminform': adminForm,
            'object_id': object_id,
            'original': obj,
            'is_popup': request.REQUEST.has_key('_popup'),
            'media': mark_safe(media),
            'inline_admin_formsets': inline_admin_formsets,
            'errors': helpers.AdminErrorList(form, formsets),
            'root_path': self.admin_site.root_path,
            'app_label': opts.app_label,
        }
        context.update(extra_context or {})
        return self.render_change_form(request, context, change=True, obj=obj)
    change_view = transaction.commit_on_success(change_view)
    
    def changelist_view(self, request, extra_context=None):
        "The 'change list' admin view for this model."
        from django.contrib.admin.views.main import ChangeList, ERROR_FLAG
        opts = self.model._meta
        app_label = opts.app_label
        if not self.has_change_permission(request, None):
            raise PermissionDenied
        try:
            cl = ChangeList(request, self.model, self.list_display, self.list_display_links, self.list_filter,
                self.date_hierarchy, self.search_fields, self.list_select_related, self.list_per_page, self)
        except IncorrectLookupParameters:
            # Wacky lookup parameters were given, so redirect to the main
            # changelist page, without parameters, and pass an 'invalid=1'
            # parameter via the query string. If wacky parameters were given and
            # the 'invalid=1' parameter was already in the query string, something
            # is screwed up with the database, so display an error page.
            if ERROR_FLAG in request.GET.keys():
                return render_to_response('admin/invalid_setup.html', {'title': _('Database error')})
            return HttpResponseRedirect(request.path + '?' + ERROR_FLAG + '=1')
        
        context = {
            'title': cl.title,
            'is_popup': cl.is_popup,
            'cl': cl,
            'has_add_permission': self.has_add_permission(request),
            'root_path': self.admin_site.root_path,
            'app_label': app_label,
        }
        context.update(extra_context or {})
        return render_to_response(self.change_list_template or [
            'admin/%s/%s/change_list.html' % (app_label, opts.object_name.lower()),
            'admin/%s/change_list.html' % app_label,
            'admin/change_list.html'
        ], context, context_instance=template.RequestContext(request))
    
    def delete_view(self, request, object_id, extra_context=None):
        "The 'delete' admin view for this model."
        opts = self.model._meta
        app_label = opts.app_label
        
        try:
            obj = self.model._default_manager.get(pk=unquote(object_id))
        except self.model.DoesNotExist:
            # Don't raise Http404 just yet, because we haven't checked
            # permissions yet. We don't want an unauthenticated user to be able
            # to determine whether a given object exists.
            obj = None
        
        if not self.has_delete_permission(request, obj):
            raise PermissionDenied
        
        if obj is None:
            raise Http404(_('%(name)s object with primary key %(key)r does not exist.') % {'name': force_unicode(opts.verbose_name), 'key': escape(object_id)})
        
        # Populate deleted_objects, a data structure of all related objects that
        # will also be deleted.
        deleted_objects = [mark_safe(u'%s: <a href="../../%s/">%s</a>' % (escape(force_unicode(capfirst(opts.verbose_name))), object_id, escape(obj))), []]
        perms_needed = set()
        get_deleted_objects(deleted_objects, perms_needed, request.user, obj, opts, 1, self.admin_site)
        
        if request.POST: # The user has already confirmed the deletion.
            if perms_needed:
                raise PermissionDenied
            obj_display = force_unicode(obj)
            obj.delete()
            
            self.log_deletion(request, obj, obj_display)
            self.message_user(request, _('The %(name)s "%(obj)s" was deleted successfully.') % {'name': force_unicode(opts.verbose_name), 'obj': force_unicode(obj_display)})
            
            if not self.has_change_permission(request, None):
                return HttpResponseRedirect("../../../../")
            return HttpResponseRedirect("../../")
        
        context = {
            "title": _("Are you sure?"),
            "object_name": force_unicode(opts.verbose_name),
            "object": obj,
            "deleted_objects": deleted_objects,
            "perms_lacking": perms_needed,
            "opts": opts,
            "root_path": self.admin_site.root_path,
            "app_label": app_label,
        }
        context.update(extra_context or {})
        return render_to_response(self.delete_confirmation_template or [
            "admin/%s/%s/delete_confirmation.html" % (app_label, opts.object_name.lower()),
            "admin/%s/delete_confirmation.html" % app_label,
            "admin/delete_confirmation.html"
        ], context, context_instance=template.RequestContext(request))
    
    def history_view(self, request, object_id, extra_context=None):
        "The 'history' admin view for this model."
        from django.contrib.admin.models import LogEntry
        model = self.model
        opts = model._meta
        app_label = opts.app_label
        action_list = LogEntry.objects.filter(
            object_id = object_id,
            content_type__id__exact = ContentType.objects.get_for_model(model).id
        ).select_related().order_by('action_time')
        # If no history was found, see whether this object even exists.
        obj = get_object_or_404(model, pk=object_id)
        context = {
            'title': _('Change history: %s') % force_unicode(obj),
            'action_list': action_list,
            'module_name': capfirst(force_unicode(opts.verbose_name_plural)),
            'object': obj,
            'root_path': self.admin_site.root_path,
            'app_label': app_label,
        }
        context.update(extra_context or {})
        return render_to_response(self.object_history_template or [
            "admin/%s/%s/object_history.html" % (app_label, opts.object_name.lower()),
            "admin/%s/object_history.html" % app_label,
            "admin/object_history.html"
        ], context, context_instance=template.RequestContext(request))

    #
    # DEPRECATED methods.
    #
    def __call__(self, request, url):
        """
        DEPRECATED: this is the old way of URL resolution, replaced by
        ``get_urls()``. This only called by AdminSite.root(), which is also
        deprecated.
        
        Again, remember that the following code only exists for
        backwards-compatibility. Any new URLs, changes to existing URLs, or
        whatever need to be done up in get_urls(), above!
        
        This function still exists for backwards-compatibility; it will be
        removed in Django 1.3.
        """
        # Delegate to the appropriate method, based on the URL.
        if url is None:
            return self.changelist_view(request)
        elif url == "add":
            return self.add_view(request)
        elif url.endswith('/history'):
            return self.history_view(request, unquote(url[:-8]))
        elif url.endswith('/delete'):
            return self.delete_view(request, unquote(url[:-7]))
        else:
            return self.change_view(request, unquote(url))

class InlineModelAdmin(BaseModelAdmin):
    """
    Options for inline editing of ``model`` instances.
    
    Provide ``name`` to specify the attribute name of the ``ForeignKey`` from
    ``model`` to its parent. This is required if ``model`` has more than one
    ``ForeignKey`` to its parent.
    """
    model = None
    fk_name = None
    formset = BaseInlineFormSet
    extra = 3
    max_num = 0
    template = None
    verbose_name = None
    verbose_name_plural = None
    
    def __init__(self, parent_model, admin_site):
        self.admin_site = admin_site
        self.parent_model = parent_model
        self.opts = self.model._meta
        super(InlineModelAdmin, self).__init__()
        if self.verbose_name is None:
            self.verbose_name = self.model._meta.verbose_name
        if self.verbose_name_plural is None:
            self.verbose_name_plural = self.model._meta.verbose_name_plural
    
    def _media(self):
        from django.conf import settings
        js = []
        if self.prepopulated_fields:
            js.append('js/urlify.js')
        if self.filter_vertical or self.filter_horizontal:
            js.extend(['js/SelectBox.js' , 'js/SelectFilter2.js'])
        return forms.Media(js=['%s%s' % (settings.ADMIN_MEDIA_PREFIX, url) for url in js])
    media = property(_media)
    
    def get_formset(self, request, obj=None, **kwargs):
        """Returns a BaseInlineFormSet class for use in admin add/change views."""
        if self.declared_fieldsets:
            fields = flatten_fieldsets(self.declared_fieldsets)
        else:
            fields = None
        if self.exclude is None:
            exclude = []
        else:
            exclude = list(self.exclude)
        defaults = {
            "form": self.form,
            "formset": self.formset,
            "fk_name": self.fk_name,
            "fields": fields,
            "exclude": exclude + kwargs.get("exclude", []),
            "formfield_callback": curry(self.formfield_for_dbfield, request=request),
            "extra": self.extra,
            "max_num": self.max_num,
        }
        defaults.update(kwargs)
        return inlineformset_factory(self.parent_model, self.model, **defaults)
    
    def get_fieldsets(self, request, obj=None):
        if self.declared_fieldsets:
            return self.declared_fieldsets
        form = self.get_formset(request).form
        return [(None, {'fields': form.base_fields.keys()})]
    
class StackedInline(InlineModelAdmin):
    template = 'admin/edit_inline/stacked.html'

class TabularInline(InlineModelAdmin):
    template = 'admin/edit_inline/tabular.html'
